Method of additive manufacturing and method of making porous particles

Abstract

A method of additive manufacturing. The method comprises: i) positioning porous particles on a substrate, the porous particles having an average porosity and comprising at least one material chosen from metals and metalloids; ii) heating at least a portion of the porous particles to a reaction temperature; and iii) exposing the porous particles to a reactant gas to form a layer comprising a non-oxide ceramic. A method of making porous particles is also disclosed.

What is claimed is: 
     
         1 . A method of additive manufacturing, the method comprising:
 i) positioning porous particles on a substrate, the porous particles having an average porosity and comprising at least one material chosen from metals and metalloids;   ii) heating at least a portion of the porous particles to a reaction temperature; and   iii) exposing the porous particles to a reactant gas to form a layer comprising a non-oxide ceramic.   
     
     
         2 . The method of  claim 1 , further comprising, prior to i), determining a desired average porosity of porous particles, the desired average porosity of the porous particles resulting in: i) a desired porosity of a 3D printed product comprising a non-oxide ceramic made from the porous particles; or ii) a desired near-net shape of the 3D printed product. 
     
     
         3 . The method of  claim 1 , wherein the non-oxide ceramic has a percent volume increase relative to the porous particles, the percent volume increase being about equal to the average porosity of the porous particles. 
     
     
         4 . The method of  claim 1 , further comprising:
 iv) positioning additional porous particles on the layer comprising the non-oxide ceramic, the additional porous particles having a second average porosity and comprising at least one material chosen from metals and metalloids; and   v) heating the additional porous particles to the reaction temperature; and   vi) exposing the additional porous particles to the reactant gas to form a second layer comprising the non-oxide ceramic; and   vii) repeating iv) to vi) a plurality of times to form a 3D printed product on the substrate.   
     
     
         5 . The method of  claim 4 , wherein the average porosity and the second average porosity are the same. 
     
     
         6 . The method of  claim 4 , wherein the 3D printed product has a near-net shape. 
     
     
         7 . The method of  claim 1 , wherein the average porosity ranges from about 10% to about 80%. 
     
     
         8 . The method of  claim 1 , wherein the material is a metal or metalloid chosen from Ti, Hf, Ta, Zr, V, Nb, Cr, Mo, Co, Ni, Tc, Os, Re, W, Mn, Fe, Ga, Al, Si, B or alloys thereof. 
     
     
         9 . The method of  claim 1 , wherein the reactant gas comprises at least one gas selected from a hydrocarbon, ammonia, nitrogen gas and boron hydrides. 
     
     
         10 . The method of  claim 1 , wherein the non-oxide ceramic comprises at least one material selected from metal nitrides, metal carbides, metal borides, metalloid nitrides, metalloid carbides and metalloid borides. 
     
     
         11 . The method of  claim 1 , wherein the method of additive manufacturing is selective laser reaction sintering. 
     
     
         12 . The method of  claim 1 , wherein the substrate is the build plate of 3D printer. 
     
     
         13 . The method of  claim 1 , wherein the porous particles do not include a polymer binder. 
     
     
         14 . A method of making porous particles, the method comprising:
 determining the percent volume increase between a precursor material and a non-oxide ceramic formed from the precursor material;   determining a desired average porosity of porous particles based on the percent volume increase; and   forming porous particles comprising the precursor material and having the desired average porosity, the precursor material comprising at least one material chosen from metals and metalloids.   
     
     
         15 . The method of  claim 14 , wherein the desired average porosity is chosen to be about the same as the percent volume increase. 
     
     
         16 . The method of  claim 14 , wherein forming the porous particle comprises reduction of a metal compound chosen from metal hydrides, metal chlorides and metal oxides. 
     
     
         17 . The method of  claim 14 , wherein forming the porous particle comprises aggregation of particles having a particle size ranging from about 10 nanometers to about 100 micrometers. 
     
     
         18 . The method of  claim 14 , wherein forming the porous particle comprises dealloying.